Enable button when 2 conditions are fulfilled

I am trying to figure out a solution to this problem:

I would like to have a function that checks if a text field is filled with text and checkbox is checked. When these conditions are fulfilled "Submit" button is enabled. If shortly after "Submit" button was enabled, user clears text field or unchecks checkbox, the "Submit" button should be disabled again.

Every time something is typed or changed in the input field or the checkbox is changed trigger a checking function. There evaluate the conditions to disable or enable the submit button. See well commented example below in the code-runner: